Vapor lock??

[cj69RR]

Well I thought I had this resolved. After about a 1/2 hour or so it will start to stumble and die. Left me stranded for about 1/2 a hour waiting for it to cool off a little before it would start and took it straight home. I've put new 3/8's line from front to back, new fuel pump, new fuel filter. The tank was new within the last 5 years. Intake is stock cast iron, carb is an edelbrock vacuum secondarys, and has a 1 inch aluminum spacer. I'm thinking of using a penolic spacer and adding a 1/4 inch return line off the filter. Any ideas or suggestions?

 

[69hemibeep]

Well I thought I had this resolved. After about a 1/2 hour or so it will start to stumble and die. Left me stranded for about 1/2 a hour waiting for it to cool off a little before it would start and took it straight home. I've put new 3/8's line from front to back, new fuel pump, new fuel filter. The tank was new within the last 5 years. Intake is stock cast iron, carb is an edelbrock vacuum secondarys, and has a 1 inch aluminum spacer. I'm thinking of using a penolic spacer and adding a 1/4 inch return line off the filter. Any ideas or suggestions?

I think your on the right track :yesnod:

 

[Jim S.]

Look at this from another forum. The guy is having pretty much the same problem. He is starting to think it is electrical.

http://board.moparts.org/ubbthreads/sho ... ost7369047

 

[dobie]

I had a somewhat similar problem a few years ago. After 15 or 20 minutes the car would shut off. No stumbling or no warning though. Just like a light switch was shut off. That issue was the pick up coil in the distributor.

 

[cj69RR]

Sounds like I'll need to check out the ignition system. Forgot to also say that it has all MSD ignition on it, distributor, coil and ignition box.

 

[69hemibeep]

Coils that are braking down act the same way.

 

[cj69RR]

I'll look and see what that ballast reads across it and ohm it out cold and hot and do the same with the coil.

 

[cj69RR]

Here's the update, checked the ohms on the ballast. And the coil. Ballast cold .6 ohms, hot .6 ohms. Coil cold .7 ohms hot .8 ohms. Checked the then ran the car till it choaked its self dead then took hot readings. So I think the ignition is good. Checked the throttle a couple of pumps on the throttle with the air cleaner off and no fuel out of the squirters. Pulled off the fuel filter no or very little fuel in the line. So I'm back to thinking I need to put the return line on this car. Ill let it sit over night and check and see what kind of fuel pressure its making when it makes it. The reason I put a bee pump was the last pump was only Manon 1 1/2 psi. New pump a couple months ago was 8-9 psi. Any other suggestions?

 

[droptop]

Vented gas cap could be clogged.

 

[cj69RR]

I've also tried it with the gas cap off and it does the same thing. I do need a new gas cap though, if you pull off fast with anything over a 1/2 tank of gass it will spill some out.

 

[zupanj]

Will it pump fuel with the filter taken off? I don't understand what a return line gets you. If the tubing was new there may have been some stuff in it and it collected at the filter. Some of the stuff might dislodge from the filter when the engine quits running and then re-packs when the pump starts up again after a short while.

 

[4spd69RR]

I also had a similar problem and it turn out to be my mech fuel pump. The little arm / lever on the pump had cracked. I had also just installed the pump several months before it started giving me problems. I thought it was electrical at first until I placed a gauge to measure volume and pressure from the pump. That's when I found the problem with little to no pressure from the pump.

 

[cj69RR]

Didn't get to check the pressure to night but I did check the filter last night and it was clean and clear of anything. Had a little fuel in it and did the blow through test and it was easy to do. The idea of a return line is to have a constant flow of fuel and not give the fuel a chance to get hot. I can just use a stock filter off a mid 80's 360 truck that has the same size inlet and outlet with a 1/4 inch return fitting on it to also regulate the pressure keep pressure at the carb. Maybe I will have time tomorrow to check the fuel pressure out.

 

[cj69RR]

Well I spent part of yesterday plumbing and wiring in an electric fuel pump. Got it leak checked and all but it ended up raining and no test drive. Maybe today?

 

[cj69RR]

The electric fuel pump seems to have fixed the vaporous lock issues. Took it for a drive and it did well, even fired. Ack up after it was shut down for just a couple minutes. Got home and checked the fuel pump for any leaks and its all good but the left rear axle seal is now leaking so that will be next on the list. Sure do enjoy driving that old car and everyone wants to know what it is. Should ha e all the bugs worked out of it soon. Did a couple of 4k shifts and man does it pull, forgot how well it did run. Enjoyed the ride.

 

[Roadcuda]

The electric fuel pump seems to have fixed the vaporous lock issues. Took it for a drive and it did well, even fired. Ack up after it was shut down for just a couple minutes. Got home and checked the fuel pump for any leaks and its all good but the left rear axle seal is now leaking so that will be next on the list. Sure do enjoy driving that old car and everyone wants to know what it is. Should ha e all the bugs worked out of it soon. Did a couple of 4k shifts and man does it pull, forgot how well it did run. Enjoyed the ride.

That's great news. Doesn't it feel great when you figure out the problems and get things running right again! :yesnod:

 

[cj69RR]

Sure does fill good to get things figured out and running right. My dad had messed with it for a year or so and just kinda gave up I think. But the fuel line was full of trash and the mechanical pump was not making any pressure either. So there has been a lot of work to get it here. Ill get that axle seal fixed up and back on the road again. The weather finally cooling off and I'll get it out more and put some miles on it.

 

[mcmopar]

I've also tried it with the gas cap off and it does the same thing. I do need a new gas cap though, if you pull off fast with anything over a 1/2 tank of gass it will spill some out.

That has always been a common problem. Years ago I saw a Superbird in a street race right in front of me spill a bunch of gas out of the filler (behind the license plate). A new cap might help - but it might not.

 

[Roadcuda]

I've also tried it with the gas cap off and it does the same thing. I do need a new gas cap though, if you pull off fast with anything over a 1/2 tank of gass it will spill some out.

That has always been a common problem. Years ago I saw a Superbird in a street race right in front of me spill a bunch of gas out of the filler (behind the license plate). A new cap might help - but it might not.

I had to change the cap on my car because I was loosing gas out of it. I found the problem when the car was parked facing up hill and saw a big gas puddle under it. Pep Boys actually had one that fit it in stock!

 

[cj69RR]

Also has a new cap for the tank. Picked up a new axle seal for the new issue. That will be a Friday or weekend deal. Still thinking I will put a return line on it just for insurance.